Adopted (black points) and mean recovered (red points) time delay as a function of redshift for faint AGN (log L₃₀₀₀ = 44.7, upper panel) and for bright AGN (log L₃₀₀₀ = 45.7, lower panel) from the main survey. Green error bars are the standard deviation that is expected in a single source measurement, as determined by the use of 100 statistically equivalent simulations. The error of the mean recovered delay is 10% of the dispersion. The other parameters have the standard values given in Table 2. The redshift gaps correspond to no satisfactory selection of the contaminated and uncontaminated bands.